LM9831  Product Folder

The LM9831 is a complete USB image scanner system on a single IC. The LM9831 provides all the functions (image sensor control, illumination control, analog front end, pixel processing function image data buffer/DRAM controller, microstepping motor controller, and USB interface) necessary to create a high performance color scanner. The LM9831 scans images in 42 bit color/14 bit gray, and has output data formats for 24 bit color/8 bit gray. the LM9831 support sensors with pixel counts of up to 16384 pixels x 3 colors (12000 dpi x 13.6 inches.)

The LM9831's low operating and suspend mode supply currents allow design of USB bus-powered scanners. The only additional active components required are an external 4Mbit or 16Mbit DRAM for data buffering and power transistors for the stepper motor.

• 14 bit ADC digitizes at up to 6Mpixels/s (2M RGB pixels/sec)
• Digital Pixel Processing provides 1200, 800, 600, 400, 300, 200, 150, and 100dpi horizontal resolution from a 1200dpi sensor and 600, 400, 300, 200, 150, 100, 75, and 50dpi horizontal resolution from a 600dpi sensor
• Provides 50-2400dpi vertical resolution in 1 dpi increments
• Pixel rate error correction for gain (shading) and offset errors
• Supports 4 or 16Mbit external DRAMs
• Multiple CCD clocking rates allows matching of CCD clock to scan resolution and pixel depth for maximum scan speed
• Stepper motor control tightly coupled with image data buffer management to maximize data transfer efficiency
• PWM stepper motor current control allows microstepping for the price of fullstepping
• USB interface for Plug and Play operation on USB-equipped computers
• Serial EEPROM option for custom Vendor and Product IDs
• Support for USB bus-powered operation
• Pixel depths of 1, 2, or 4 bits are packed into bytes for faster scans of line art and low pixel depth images
• Supports 3 channel CCDs and 1 channel CIS sensors
• 3 (R, G, and B) 12-bit, user-programmable gamma correction tables
• Compatible with a wide range of color linear CCDs and Contact Image Sensors (CIS)
• Operates with 48MHz external crystal
• Internal bandgap voltage reference
• 100 pin TQFP package

• Color Flatbed Document Scanners
• Color Sheetfed Document Scanners